We’re still months away from kickoff for Super Bowl 50 in Santa Clara, but the VACANCY signs are already popping up like mushrooms all over the Bay Area.

They are not, however, popping up at hotels, many of which are already sold out.

Joining what has become an annual tradition that gathers more steam each winter, scores of residents of the Bay Area hosting the big game are jumping into the hospitality business, using sites like Airbnb and VRBO.com to rent out their homes, apartments, cottages and spare bedrooms to the football faithful coming to town.

“The surge has already begun,” said Riccardo Ulivi with San Francisco-based Airbnb. “We’ve got more than 7,000 available listings already for Super Bowl weekend and we’re seeing a bigger surge in demand here in the Bay Area than we did for the last one in Phoenix. We’re currently seeing three-and-a-half times more searches than normal for that weekend” of Feb. 6-8.

Driving the home-hosting frenzy, which Airbnb says began with bookings as early as last January, is that many of the larger hotel properties in San Francisco, where many Super Bowl events will be held, and Santa Clara, home of Levi’s Stadium, have already been booked solid. Many of those rooms are controlled early on by the NFL for its owners, guests and teams, with one hotelier complaining that the league uses “an onerous contract” that prevents a hotel from renting out even its unblocked rooms without the NFL’s permission. (The league did not respond to a request for comment.)

A check of area hotels shows a dearth of available rooms. Close to the stadium, not only are all of the nearly 800 rooms at the Santa Clara Marriott already sold out for Super Bowl weekend, but a reservations clerk couldn’t even quote a hypothetical rate: “They don’t give me a room rate,” she said, “unless I can sell a room — and for those dates I can’t.”

And so into the void rushes an army of wannabe landlords like Reuven Shelef, the 45-year-old head of a management-consulting firm who’s renting out his four-bedroom, two-bath home in Sunnyvale for the big event. He became an Airbnb host for the first time a few months back, even though he wasn’t crazy about the idea.

“I didn’t want to do all the prep work, but my wife was excited about the idea of becoming hosts,” he said. “So to get her off my back, I said OK.”

In a flash, they had their first paying guests, who took the house for three weeks while Shelef and his family took off on vacation.

“For Super Bowl, my plan is to carefully research the market rates for those dates and then list it, start fielding candidates, and then take off Super Bowl weekend for some exotic place,” said Shelef. “We’ll have to take off, because it’ll be too expensive to stay around here that weekend. Maybe Belize, or Costa Rica, or Hawaii to see that erupting volcano.”

Isn’t he worried about Super Bowl party animals trashing his pad while he’s gazing at the very active Kilauea volcano?

“There is a risk, because we might get first-time renters who couldn’t care less about how we might review them on Airbnb after their stay,” he said. “So we might prepare the house a bit differently this time, leave no valuables or computers like we have in the past. But then again, who’s going to pay $1,000 a night for our place and then destroy it?”

Signs of the surge’s momentum are everywhere. On HomeAway, which caters to owners of second homes and vacation properties, Santa Clara shows 58 listings this week, up from just 19 in April. San Jose jumped from 57 to 115, while Palo Alto’s inventory climbed from 43 four months ago to 74 today. Spokesman Adam Annen said this Super Bowl uptick is not surprising.

“Super Bowls draw hundreds of thousands of people to events outside of the actual game,” he said about an event that organizers predict will draw one million visitors to the Bay Area. “And all these people simply can’t be accommodated by the existing hotel infrastructure. So you have people putting up their homes to take advantage of the demand.”

Super Bowl 49 in Glendale, located nine miles outside Phoenix, saw a more than 300-percent price hike above usual rates, according to HomeAway, averaging $850 a night.

In the Glendale/Phoenix area, rates started as low as $617 for the weekend all the way up to the site’s most expensive listing of $225,000 for seven nights in a $10 million-valued home. The average weekly rate was around $8,000, a Super Bowl-sized jump from the normal rate of $1,600.

Ian McHenry, co-founder and president of Beyond Pricing, which helps hosts figure out what to charge, said that greed is also part of this annual ritual. “We’ve seen this cycle over and over again, whether it’s a Super Bowl or a Grateful Dead concert or the pope visiting, where all the hotels sell out and then the news stories lead everyone to list their home on these sites,” he said. “Suddenly, you have a flood of supply with people asking outrageous amounts like $2,000 a night. People equate a listing with a booking, but it often doesn’t turn out that way.”

Still, the thought of easy income has proved hard to resist for Paul Arys, a 30-year-old account manager at Fiserv whose Santa Clara home sits across the street from the stadium.

“We started renting out a bedroom in February to pick up some extra income to pay our bills and save for a trip,” said Arys. “It’s pretty good since you can see a profile of the person who’ll be staying in your house. We haven’t gotten any ax murderers that we know of.”

Asking $2,000 for his room, Arys has already fielded a handful of queries from “people saying, ‘If our team makes the Super Bowl, we’d like to rent it for the week.'” And while they wait to rent out the bedroom, Arys and his wife are already thinking ahead:

“We’ll probably turn our garage into another bedroom we can rent out for Super Bowl,” he said. “We’re just waiting for permits.”

* According to Cheaphotels.org, only one in 10 hotels in the greater Phoenix region still had vacancies shortly before Super Bowl weekend, with four- and five-star hotels already sold out.* Even budget hotels raised their prices in Glendale, averaging a 300% price hike above their usual rates to $850 per night.* In the Glendale/Phoenix area, rates started as low as $617 for the weekend on the low-end to the most expensive listing of $225,000 for seven nights in a $10-million home.* The average rates (from Friday, Jan. 30, 2015, to Monday, Feb. 2) were around $8,000 (typically 2-3 bedroom homes, which can sleep an average of 8-10 people), an increase from $1,600/week.

AND MORE …* Airbnb currently has more than 7,000 available listings in the Bay Area for Super Bowl 50 weekend.